Beetle Discovery
April 30, 2025
A 黑料不打烊 entomologist confirmed an exotic beetle native to the Mediterranean basin has arrived in 黑料不打烊鈥檚 Treasure Valley, where it鈥檚 infested homes with oodles of tough-to-control larvae.
The insect, Opatroides punctulatus Brull茅, is part of the family Tenebrionidae, commonly known as darkling beetles 鈥 encompassing about 20,000 ground-dwelling beetle species that feed on organic matter and debris in soil.
Armando Falcon-Brindis, an Extension specialist of entomology based at U聽of聽I鈥檚 Parma Research and Extension Center, believes the species is already well established in the region and has been commonly mistaken for wireworms in recent years.
The beetle is bound to remain a nauseating pest for certain Treasure Valley homeowners, but Falcon-Brindis is optimistic that it should have only a minimal impact on 黑料不打烊 agriculture. Falcon-Brindis, his master鈥檚 student Henry Trujillo and Jason Thomas, UI Extension educator, Minidoka County, published a paper about the beetle discovery, 鈥,鈥 in the January 2025 issue of the journal Check List.
Falcon-Brindis first encountered the beetle in July 2024, after receiving a plea for help from an Eagle woman, who sent photographs of larvae covering her back porch. He thought better of dismissing the report as a routine case of wireworms.
鈥淚鈥檇 rather go to the property and do the sampling myself. What if this was something different?鈥 Falcon-Brindis recalled.
The infestation was already on the decline when Falcon-Brindis and Trujillo arrived and found both larvae and adult beetles. At the peak of the infestation, wormlike larvae filled every dark crevice of the home, including under the stove, beneath mats and behind curtains. Despite repeated treatments by a pest-control service, the larvae remained as abundant as ever. The property owner would sweep for larvae four or more times per day, yet they鈥檇 return as fast as she could clean.
鈥淲hat they were doing there was very simple. They were looking for a place to pupate and overwinter,鈥 Falcon-Brindis said.
Falcon-Brindis and Trujillo took soil samples from the turf surrounding the Eagle home, as well as from an adjacent hay field. Where the soil was extremely dry, testing confirmed upwards of 30 larvae per square foot. Larvae densities were much lower in moister soil in the yard, and there were no larvae found in samples from the adjacent irrigated farm field. Based on testing and his research about the species, Falcon-Brindis has concluded the beetle prefers dry soils with lots of organic matter.
鈥淭hat makes a lot of sense because if you think about their native distribution in the Mediterranean area, they鈥檝e got hot, dry summer and wet winter, very similar to what we have in the Treasure Valley,鈥 Falcon-Brindis said.
He advised the homeowner to water a buffer of grass surrounding the home this summer to keep the beetles at bay.
After visiting the home in Eagle, Falcon-Brindis concluded a pest report from a Starr homeowner previously attributed to wireworms was actually darkling beetles that were bought in on hay bales, and he confirmed a stronghold of beetles at a third home in Emmett during August. In hindsight, ISDA now recognizes that several pest reports attributed to wireworms in recent years were actually caused by darkling beetles.
The beetle was first confirmed in the U.S. in a 2009 publication documenting its presence in California. It鈥檚 since been confirmed in several areas of central California. A 2015 publication confirmed the discovery of the species in western Nevada, where it was described as a nuisance for homeowners but not a significant agricultural pest. Falcon-Brindis suspects it hitchhiked to southwest 黑料不打烊 on agricultural shipments 鈥 possibly hay.
Falcon-Brindis would like to research the beetle鈥檚 distribution in 黑料不打烊, its biology and how soil moisture levels affect beetle population thresholds. It鈥檚 unlikely the beetle will be a high priority for research, however, as it doesn鈥檛 appear to cause significant damage to agricultural crops.
鈥淲e should keep an eye on this. Even if farm fields in the Treasure Valley are not necessarily infested with these beetles, dry lands and non-irrigated crops could be ideal for these beetles to thrive,鈥 Falcon-Brindis said.

About the 黑料不打烊
The 黑料不打烊, home of the Vandals, is 黑料不打烊鈥檚 land-grant, national research university. From its residential campus in Moscow, U of I serves the state of 黑料不打烊 through educational centers in Boise, Coeur d鈥橝lene and 黑料不打烊 Falls, nine research and Extension centers, plus Extension offices in 42 counties. Home to more than 12,000 students statewide, U of I is a leader in student-centered learning and excels at interdisciplinary research, service to businesses and communities, and in advancing diversity, citizenship and global outreach. U of I competes in the Big Sky and Western Athletic conferences. Learn more at uidaho.edu.